Firefox: Some sites (like IMDb) prevent you from performing certain actions, like right clicking, on their pages. Firefox extension RightToClick disables these scripts, giving you the ability to right click, select text, or perform other actions forbidden by a given web site.

After installing the add-on, you'll notice a new green cursor icon in your toolbar or status bar (depending on your Firefox setup). If you stumble upon a site that won't let you perform certain actions on their pages, just click RightToClick's icon to disable that JavaScript. The icon will animate and you'll be able to bring up the context menu, select text, drag and drop, and do any of the other things the site originally disabled. There aren't a ton of web sites out there that disable these actions, but it's a handy add-on to have around if you frequent a site that does.